I. Field of the Invention
The present invention pertains to machines for collecting, reducing, compacting and removing wooden materials, and more particularly to drum chippers and shredders.
II. Description of the Background
Urban removal of wood and debris at the curbside is presently accomplished using a number of labor intensive or environmentally unfriendly methods. These methods include burning, bundling at curbside with rope or twine, and collection by city crews using portable shredders.
Burning, although less used today than years past, results in smoke and pollutants being discharged into the air. This method is particularly a problem during days of high pressure which forces smoke to hover at low altitudes and create a nuisance. As a result, burning has been banned by law in many communities.
Most urban collection of wood is currently done by bundling twigs and branches with rope or twine and setting then at the curbside for collection. The bundles are collected by crews, placed in trucks and transported to land fills or compost piles for disposal. One problem with bundling is that compliance with proper collection rules is low. Compliance problems typically arise when people bundle branches in excess of the size or weight designated by collection crews. Problems can also arise when people fail to properly tie the bundles. Bundles that fail to comply with collection rules are typically left at the curbside by collection crews and may sit for weeks thereby becoming an eye sore and a road hazard.
Another method of removing wood debris is with portable high-speed shredders. To remove curbside debris, crews hand-feed branches into a shredder. The hand-fed branches are quickly reduced and blown into the back of a truck, often with the aid of a high-power blower system. Although this method is fairly effective at reducing wood debris, the method fails in many other respects. First, the method provides an inefficient use of labor, as it requires multiple crewmembers to drive the truck and handle the branches. Secondly, present day chippers and shredders generate large amounts of noise pollution. Excessive noise pollution arises from both the high speed cutting implements and from the high power blower systems. Noise pollution also arises from high speed impacting of the cutting implements upon the material being shredded.
Present day shredders also are very dangerous. When branches are hand fed into rotating high-speed blades, the blades quickly grab and pull the branches. If an operator fails to pay close attention to the job at hand, the operator can be pulled into the shredder and severely injured. Another hazard arises from flying debris. Flying debris occurs from splintered wood being ejected back towards the operator from the high-speed cutting blades. Because of the dangers involved in using high-speed portable shredders, the inefficient use of labor, and the excessive noise pollution generated, methods of urban wood removal are in need of improvement.
Therefore, what is needed for effective urban collection of wood debris is a quieter, lower-speed shredder that is safer and needs only a single person to operate.
The present invention addresses the above mentioned problems and others by providing a machine for collecting and shredding wood which includes: a prime carrier; a debris collector operatively attached to the prime carrier; a shredder assembly attached to the prime carrier, the shredder assembly having a wood input and an output; a storage bin for holding reduced wood, the storage bin attached to the prime carrier; and a conveyor disposed between the output and the storage bin for moving reduced wood away from the output of the shredder.
In another aspect of the invention, there is provided a machine for collecting and shredding wood as described above which further includes a compactor for receiving wood from the conveyor and compressing the wood into the storage bin.
In still another aspect of the invention there is provided a tapered drum shredder for reducing wood. A preferred drum shredder includes a housing; a tapered cutting drum rotatably mounted within the housing; an anvil adjacent to the cutting drum; at least one cutting blade disposed about an outer surface of the cutting drum to provide a compound cutting angle; and a drive connected to the drum to provide rotation. The cutting drum is preferably tapered with a nose or nose end and a back or butt end which forms a cone, frustum or cone like shape, e.g. a cutting cone. A cutting cone provides a cutting surface with a plurality of cutting speeds and variable torque. The cutting drum preferably includes a plurality of cutting cones connected in series. The drum shredder preferably includes a plurality of cutting drums.
Preferably the drum shredder has an anvil; a variable torque, rotatable cutting drum, which cooperates with the anvil to form an acute cutting angle; at least one cutting blade disposed about an outer surface of the cutting drum; and a drive operatively connected to the drum for rotation.
In a preferred embodiment the drum shredder has a gravity feed chute with substantially vertical walls and a floor. In another embodiment the feed chute is substantially horizontal. In still another embodiment the feed chute is a side feed.
In one embodiment of the invention the at least one cutting blade is a plurality of cutting blades. In a preferred embodiment of the invention each cutting cone, or each section of the cutting drum has at least one cutting blade, which may extend along the length of the associated cutting cone or section. In another embodiment of the invention, each cutting blade may be a removable hammer with a reversible cutting edge.
In a preferred embodiment of the present invention there is provided a drum shredder having more than one cutting drum rotatably mounted in the shredder. The drums may share the same drive and be connected together or alternatively may have separate drives. In a preferred embodiment a plurality of cutting drums are mounted side by side. In a more preferred embodiment, a plurality of cutting drums are mounted coaxial with one another. In a most preferred embodiment the plurality of cutting drums are mounted coaxial with one another and fixed nose to nose.
In one aspect of the present invention, there is provided a shredder having a discharge assembly adapted to receive at least two major streams of chips having different discharge directions and deposit then efficiently into a storage bin, or away from the shredder assembly. In a preferred embodiment hereof the discharge assembly includes a bellyband, a transition in communication with the bellyband, and a discharge port in communication with the transition, wherein the bellyband conforms to and follows with the cutting drum for guiding reduced material to the transition.
For a more complete understanding of the present invention, reference is now made to the accompanying drawings and following detailed description of the preferred embodiments. Throughout the several figures and views, like symbols refer to like elements.